[CentOS] Clustering

On 2/4/2010 3:17 PM, Bo Lynch wrote:
>> Right know we have about 30 or so linux servers scattered through out or
> district. Was looking at ways of consolidating and some sort of redundancy
> would be nice.
> Will clustering not work with certain apps? We have a couple mysql dbases,
> oracle database, smb shares, nfs, email, and web servers.
Each app has it's own best way to provide the redundancy and
auto-failover and it's own set of tradeoffs of the added complexity vs.
the possible reduced downtime if the primary fails.
I'd balance the options against the low-tech method of having raid
mirrors in swappable bays with a spare similar server chassis or two
around plus regular backups kept at a different location. The raid lets
you continue in the likely event of a disk failure so you can repair it
at a convenient time. Other failures (motherboard, power supply) are
less likely but can be handled by swapping the drives into an alternate
chassis (and with Centos you'll need to re-assign the IP addresses that
are tied to the old NIC mac addresses) with a small amount of downtime.
And the backups cover things like operator or software errors (that
would wipe a cluster too) or a building-level disaster that destroys the
disks or the primary and spare chassis at the same time. Some apps may
be worth the effort to do better.
--
Les Mikesell
lesmikesell at gmail.com